xref: /openbmc/qemu/qapi/string-output-visitor.c (revision b45c03f5)
1 /*
2  * String printing Visitor
3  *
4  * Copyright Red Hat, Inc. 2012
5  *
6  * Author: Paolo Bonzini <pbonzini@redhat.com>
7  *
8  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
9  * See the COPYING.LIB file in the top-level directory.
10  *
11  */
12 
13 #include "qemu-common.h"
14 #include "qapi/string-output-visitor.h"
15 #include "qapi/visitor-impl.h"
16 #include "qemu/host-utils.h"
17 #include <math.h>
18 #include "qemu/range.h"
19 
20 enum ListMode {
21     LM_NONE,             /* not traversing a list of repeated options */
22     LM_STARTED,          /* start_list() succeeded */
23 
24     LM_IN_PROGRESS,      /* next_list() has been called.
25                           *
26                           * Generating the next list link will consume the most
27                           * recently parsed QemuOpt instance of the repeated
28                           * option.
29                           *
30                           * Parsing a value into the list link will examine the
31                           * next QemuOpt instance of the repeated option, and
32                           * possibly enter LM_SIGNED_INTERVAL or
33                           * LM_UNSIGNED_INTERVAL.
34                           */
35 
36     LM_SIGNED_INTERVAL,  /* next_list() has been called.
37                           *
38                           * Generating the next list link will consume the most
39                           * recently stored element from the signed interval,
40                           * parsed from the most recent QemuOpt instance of the
41                           * repeated option. This may consume QemuOpt itself
42                           * and return to LM_IN_PROGRESS.
43                           *
44                           * Parsing a value into the list link will store the
45                           * next element of the signed interval.
46                           */
47 
48     LM_UNSIGNED_INTERVAL,/* Same as above, only for an unsigned interval. */
49 
50     LM_END
51 };
52 
53 typedef enum ListMode ListMode;
54 
55 struct StringOutputVisitor
56 {
57     Visitor visitor;
58     bool human;
59     GString *string;
60     bool head;
61     ListMode list_mode;
62     union {
63         int64_t s;
64         uint64_t u;
65     } range_start, range_end;
66     GList *ranges;
67 };
68 
69 static void string_output_set(StringOutputVisitor *sov, char *string)
70 {
71     if (sov->string) {
72         g_string_free(sov->string, true);
73     }
74     sov->string = g_string_new(string);
75     g_free(string);
76 }
77 
78 static void string_output_append(StringOutputVisitor *sov, int64_t a)
79 {
80     Range *r = g_malloc0(sizeof(*r));
81     r->begin = a;
82     r->end = a + 1;
83     sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
84 }
85 
86 static void string_output_append_range(StringOutputVisitor *sov,
87                                        int64_t s, int64_t e)
88 {
89     Range *r = g_malloc0(sizeof(*r));
90     r->begin = s;
91     r->end = e + 1;
92     sov->ranges = g_list_insert_sorted_merged(sov->ranges, r, range_compare);
93 }
94 
95 static void format_string(StringOutputVisitor *sov, Range *r, bool next,
96                           bool human)
97 {
98     if (r->end - r->begin > 1) {
99         if (human) {
100             g_string_append_printf(sov->string, "0x%" PRIx64 "-0x%" PRIx64,
101                                    r->begin, r->end - 1);
102 
103         } else {
104             g_string_append_printf(sov->string, "%" PRId64 "-%" PRId64,
105                                    r->begin, r->end - 1);
106         }
107     } else {
108         if (human) {
109             g_string_append_printf(sov->string, "0x%" PRIx64, r->begin);
110         } else {
111             g_string_append_printf(sov->string, "%" PRId64, r->begin);
112         }
113     }
114     if (next) {
115         g_string_append(sov->string, ",");
116     }
117 }
118 
119 static void print_type_int(Visitor *v, int64_t *obj, const char *name,
120                            Error **errp)
121 {
122     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
123     GList *l;
124 
125     switch (sov->list_mode) {
126     case LM_NONE:
127         string_output_append(sov, *obj);
128         break;
129 
130     case LM_STARTED:
131         sov->range_start.s = *obj;
132         sov->range_end.s = *obj;
133         sov->list_mode = LM_IN_PROGRESS;
134         return;
135 
136     case LM_IN_PROGRESS:
137         if (sov->range_end.s + 1 == *obj) {
138             sov->range_end.s++;
139         } else {
140             if (sov->range_start.s == sov->range_end.s) {
141                 string_output_append(sov, sov->range_end.s);
142             } else {
143                 assert(sov->range_start.s < sov->range_end.s);
144                 string_output_append_range(sov, sov->range_start.s,
145                                            sov->range_end.s);
146             }
147 
148             sov->range_start.s = *obj;
149             sov->range_end.s = *obj;
150         }
151         return;
152 
153     case LM_END:
154         if (sov->range_end.s + 1 == *obj) {
155             sov->range_end.s++;
156             assert(sov->range_start.s < sov->range_end.s);
157             string_output_append_range(sov, sov->range_start.s,
158                                        sov->range_end.s);
159         } else {
160             if (sov->range_start.s == sov->range_end.s) {
161                 string_output_append(sov, sov->range_end.s);
162             } else {
163                 assert(sov->range_start.s < sov->range_end.s);
164 
165                 string_output_append_range(sov, sov->range_start.s,
166                                            sov->range_end.s);
167             }
168             string_output_append(sov, *obj);
169         }
170         break;
171 
172     default:
173         abort();
174     }
175 
176     l = sov->ranges;
177     while (l) {
178         Range *r = l->data;
179         format_string(sov, r, l->next != NULL, false);
180         l = l->next;
181     }
182 
183     if (sov->human) {
184         l = sov->ranges;
185         g_string_append(sov->string, " (");
186         while (l) {
187             Range *r = l->data;
188             format_string(sov, r, l->next != NULL, true);
189             l = l->next;
190         }
191         g_string_append(sov->string, ")");
192     }
193 }
194 
195 static void print_type_size(Visitor *v, uint64_t *obj, const char *name,
196                            Error **errp)
197 {
198     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
199     static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
200     uint64_t div, val;
201     char *out;
202     int i;
203 
204     if (!sov->human) {
205         out = g_strdup_printf("%"PRIu64, *obj);
206         string_output_set(sov, out);
207         return;
208     }
209 
210     val = *obj;
211 
212     /* The exponent (returned in i) minus one gives us
213      * floor(log2(val * 1024 / 1000).  The correction makes us
214      * switch to the higher power when the integer part is >= 1000.
215      */
216     frexp(val / (1000.0 / 1024.0), &i);
217     i = (i - 1) / 10;
218     assert(i < ARRAY_SIZE(suffixes));
219     div = 1ULL << (i * 10);
220 
221     out = g_strdup_printf("%"PRIu64" (%0.3g %c%s)", val,
222                           (double)val/div, suffixes[i], i ? "iB" : "");
223     string_output_set(sov, out);
224 }
225 
226 static void print_type_bool(Visitor *v, bool *obj, const char *name,
227                             Error **errp)
228 {
229     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
230     string_output_set(sov, g_strdup(*obj ? "true" : "false"));
231 }
232 
233 static void print_type_str(Visitor *v, char **obj, const char *name,
234                            Error **errp)
235 {
236     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
237     char *out;
238 
239     if (sov->human) {
240         out = *obj ? g_strdup_printf("\"%s\"", *obj) : g_strdup("<null>");
241     } else {
242         out = g_strdup(*obj ? *obj : "");
243     }
244     string_output_set(sov, out);
245 }
246 
247 static void print_type_number(Visitor *v, double *obj, const char *name,
248                               Error **errp)
249 {
250     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
251     string_output_set(sov, g_strdup_printf("%f", *obj));
252 }
253 
254 static void
255 start_list(Visitor *v, const char *name, Error **errp)
256 {
257     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
258 
259     /* we can't traverse a list in a list */
260     assert(sov->list_mode == LM_NONE);
261     sov->list_mode = LM_STARTED;
262     sov->head = true;
263 }
264 
265 static GenericList *
266 next_list(Visitor *v, GenericList **list, Error **errp)
267 {
268     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
269     GenericList *ret = NULL;
270     if (*list) {
271         if (sov->head) {
272             ret = *list;
273         } else {
274             ret = (*list)->next;
275         }
276 
277         if (sov->head) {
278             if (ret && ret->next == NULL) {
279                 sov->list_mode = LM_NONE;
280             }
281             sov->head = false;
282         } else {
283             if (ret && ret->next == NULL) {
284                 sov->list_mode = LM_END;
285             }
286         }
287     }
288 
289     return ret;
290 }
291 
292 static void
293 end_list(Visitor *v, Error **errp)
294 {
295     StringOutputVisitor *sov = DO_UPCAST(StringOutputVisitor, visitor, v);
296 
297     assert(sov->list_mode == LM_STARTED ||
298            sov->list_mode == LM_END ||
299            sov->list_mode == LM_NONE ||
300            sov->list_mode == LM_IN_PROGRESS);
301     sov->list_mode = LM_NONE;
302     sov->head = true;
303 
304 }
305 
306 char *string_output_get_string(StringOutputVisitor *sov)
307 {
308     char *string = g_string_free(sov->string, false);
309     sov->string = NULL;
310     return string;
311 }
312 
313 Visitor *string_output_get_visitor(StringOutputVisitor *sov)
314 {
315     return &sov->visitor;
316 }
317 
318 static void free_range(void *range, void *dummy)
319 {
320     g_free(range);
321 }
322 
323 void string_output_visitor_cleanup(StringOutputVisitor *sov)
324 {
325     if (sov->string) {
326         g_string_free(sov->string, true);
327     }
328 
329     g_list_foreach(sov->ranges, free_range, NULL);
330     g_list_free(sov->ranges);
331     g_free(sov);
332 }
333 
334 StringOutputVisitor *string_output_visitor_new(bool human)
335 {
336     StringOutputVisitor *v;
337 
338     v = g_malloc0(sizeof(*v));
339 
340     v->string = g_string_new(NULL);
341     v->human = human;
342     v->visitor.type_enum = output_type_enum;
343     v->visitor.type_int = print_type_int;
344     v->visitor.type_size = print_type_size;
345     v->visitor.type_bool = print_type_bool;
346     v->visitor.type_str = print_type_str;
347     v->visitor.type_number = print_type_number;
348     v->visitor.start_list = start_list;
349     v->visitor.next_list = next_list;
350     v->visitor.end_list = end_list;
351 
352     return v;
353 }
354